Reducing the Energy Penalty Costs of Postcombustion CCS Systems with Amine-Storage

2012 ◽  
Vol 46 (2) ◽  
pp. 1243-1252 ◽  
Author(s):  
Dalia Patiño-Echeverri ◽  
David C. Hoppock
Keyword(s):  
Penalty Costs ◽  
Amine Storage ◽  
Energy Penalty

scholarly journals The Potential of Gas Switching Partial Oxidation Using Advanced Oxygen Carriers for Efficient H2 Production with Inherent CO2 Capture

2021 ◽  
Vol 11 (10) ◽  
pp. 4713
Author(s):  
Carlos Arnaiz del Pozo ◽  
Schalk Cloete ◽  
Ángel Jiménez Álvaro ◽  
Felix Donat ◽  
Shahriar Amini
Keyword(s):  
Partial Oxidation ◽  
Co2 Capture ◽  
Oxygen Carrier ◽  
H2 Production ◽  
Advanced Materials ◽  
Oxygen Carriers ◽  
Large Power ◽  
Steam Methane ◽  
Hydrogen Supply ◽  
Energy Penalty

The hydrogen economy has received resurging interest in recent years, as more countries commit to net-zero CO2 emissions around the mid-century. “Blue” hydrogen from natural gas with CO2 capture and storage (CCS) is one promising sustainable hydrogen supply option. Although conventional CO2 capture imposes a large energy penalty, advanced process concepts using the chemical looping principle can produce blue hydrogen at efficiencies even exceeding the conventional steam methane reforming (SMR) process without CCS. One such configuration is gas switching reforming (GSR), which uses a Ni-based oxygen carrier material to catalyze the SMR reaction and efficiently supply the required process heat by combusting an off-gas fuel with integrated CO2 capture. The present study investigates the potential of advanced La-Fe-based oxygen carrier materials to further increase this advantage using a gas switching partial oxidation (GSPOX) process. These materials can overcome the equilibrium limitations facing conventional catalytic SMR and achieve direct hydrogen production using a water-splitting reaction. Results showed that the GSPOX process can achieve mild efficiency improvements relative to GSR in the range of 0.6–4.1%-points, with the upper bound only achievable by large power and H2 co-production plants employing a highly efficient power cycle. These performance gains and the avoidance of toxicity challenges posed by Ni-based oxygen carriers create a solid case for the further development of these advanced materials. If successful, results from this work indicate that GSPOX blue hydrogen plants can outperform an SMR benchmark with conventional CO2 capture by more than 10%-points, both in terms of efficiency and CO2 avoidance.

scholarly journals Direct observation of a coil-to-helix contraction triggered by vinculin binding to talin

2020 ◽  
Vol 6 (21) ◽  
pp. eaaz4707 ◽  
Author(s):  
Rafael Tapia-Rojo ◽  
Alvaro Alonso-Caballero ◽  
Julio M. Fernandez
Keyword(s):  
Focal Adhesions ◽  
Interaction Force ◽  
Magnetic Tweezers ◽  
Feedback Mechanism ◽  
Force Transmission ◽  
Mechanical Coupling ◽  
Negative Feedback Mechanism ◽  
The Reformation ◽  
Energy Penalty ◽  
First Time

Vinculin binds unfolded talin domains in focal adhesions, which recruits actin filaments to reinforce the mechanical coupling of this organelle. However, it remains unknown how this interaction is regulated and its impact on the force transmission properties of this mechanotransduction pathway. Here, we use magnetic tweezers to measure the interaction between vinculin head and the talin R3 domain under physiological forces. For the first time, we resolve individual binding events as a short contraction of the unfolded talin polypeptide caused by the reformation of the vinculin-binding site helices, which dictates a biphasic mechanism that regulates this interaction. Force favors vinculin binding by unfolding talin and exposing the vinculin-binding sites; however, the coil-to-helix contraction introduces an energy penalty that increases with force, defining an optimal binding regime. This mechanism implies that the talin-vinculin-actin association could operate as a negative feedback mechanism to stabilize force on focal adhesions.

scholarly journals Bayesian Quickest Detection Problems for Some Diffusion Processes

2013 ◽  
Vol 45 (1) ◽  
pp. 164-185 ◽  
Author(s):  
Pavel V. Gapeev ◽  
Albert N. Shiryaev
Keyword(s):  
Diffusion Processes ◽  
Free Boundary Problems ◽  
Three Dimensional ◽  
Parabolic Type ◽  
Value Functions ◽  
Weighted Likelihood ◽  
Likelihood Ratios ◽  
Boundary Problems ◽  
Detection Delay ◽  
Penalty Costs

We study the Bayesian problems of detecting a change in the drift rate of an observable diffusion process with linear and exponential penalty costs for a detection delay. The optimal times of alarms are found as the first times at which the weighted likelihood ratios hit stochastic boundaries depending on the current observations. The proof is based on the reduction of the initial problems into appropriate three-dimensional optimal stopping problems and the analysis of the associated parabolic-type free-boundary problems. We provide closed-form estimates for the value functions and the boundaries, under certain nontrivial relations between the coefficients of the observable diffusion.

scholarly journals Transport and storage of serotonin by thrombin-treated platelets.

1975 ◽  
Vol 65 (2) ◽  
pp. 359-372 ◽  
Author(s):  
H J Reimers ◽  
D J Allen ◽  
I A Feuerstein ◽  
J F Mustard
Keyword(s):  
Storage Capacity ◽  
Platelet Membrane ◽  
Transport Rate ◽  
Primary Reason ◽  
High Concentration ◽  
Serotonin Content ◽  
Amine Storage ◽  
Storage Granules ◽  
And Storage ◽  
Amine Storage Granules

Repeated thrombin treatment of washed platelets prepared from rabbits can decrease the serotonin content of the platelets by about 80%. When these platelets are deaggregated they reaccumulate serotonin but their storage capacity for serotonin is reduced by about 60%. If thrombin-pretreated platelets are allowed to equilibrate with a high concentration of serotonin (123 mu M), they release a smaller percentage of their total serotonin upon further thrombin treatment, in comparison with the percentage of serotonin released from control platelets equilibrated with the same concentration of serotonin calculations indicate that in thrombin-treated platelets reequilibrated with serotonin, two-thirds of the serotonin is in the granule compartment and one-third is in the extragranular compartment, presumably the cytoplasm. Analysis of the exchange of serotonin between the suspending fluid and the platelets showed that thrombin treatment does not alter the transport rate of serotonin across the platelet membrane and does not cause increased diffusion of serotonin from the platelets into the suspending fluid. The primary reason for the reduced serotonin accumulation by the thrombin-treated platelets appears to be loss of amine storage granules or of the storage capacity within the granules.

scholarly journals Blind crystal structure prediction of a novel second polymorph of 1-hydroxy-7-azabenzotriazole

2006 ◽  
Vol 62 (4) ◽  
pp. 642-650 ◽  
Author(s):  
Harriott Nowell ◽  
Christopher S. Frampton ◽  
Julie Waite ◽  
Sarah L. Price
Keyword(s):  
Crystal Structure ◽  
Structure Prediction ◽  
Structure Refinement ◽  
Lattice Energy ◽  
Polymorphic Form ◽  
Crystal Structure Prediction ◽  
Blind Test ◽  
Coupling Reagent ◽  
Energy Penalty ◽  
Alcohol Solvents

The commercially available peptide coupling reagent 1-hydroxy-7-azabenzotriazole has been shown to crystallize in two polymorphic forms. The two polymorphs differ in their hydrogen-bonding motif, with form I having an R_2^2(10) dimer motif and form II having a C(5) chain motif. The previously unreported form II was used as an informal blind test of computational crystal structure prediction for flexible molecules. The crystal structure of form II has been successfully predicted blind from lattice-energy minimization calculations following a series of searches using a large number of rigid conformers. The structure for form II was the third lowest in energy with form I found as the global minimum, with the energy calculated as the sum of the ab initio intramolecular energy penalty for conformational distortion and the intermolecular lattice energy which is calculated from a distributed multipole representation of the charge density. The predicted structure was sufficiently close to the experimental structure that it could be used as a starting model for crystal structure refinement. A subsequent limited polymorph screen failed to yield a third polymorphic form, but demonstrated that alcohol solvents are implicated in the formation of the form I dimer structure.

What are the Potential Benefits of Including Latent Storage in Common Wallboard?

1995 ◽  
Vol 117 (4) ◽  
pp. 318-325 ◽  
Author(s):  
T. K. Stovall ◽  
J. J. Tomlinson
Keyword(s):  
Comfort Level ◽  
Load Management ◽  
Storage Device ◽  
Time Period ◽  
Payback Time ◽  
Potential Applications ◽  
Energy Penalty ◽  
Potential Benefits ◽  
Save Energy ◽  
Change Material

Previous work has shown that wallboard can be successfully manufactured to contain up to 30 percent phase-change material (PCM), or wax, thus enabling this common building material to serve as a thermal energy storage device. The PCM wallboard was analyzed for passive solar applications and found to save energy with a reasonable payback time period of five years. Further evaluations of the wallboard are reported in this paper. This analysis looks at potential applications of PCM wallboard as a load management device and as a comfort enhancer. Results show that the wallboard is ineffective in modifying the comfort level but can provide significant load management relief. In some applications the load management strategy also serves to save a small amount of energy, in others there is a small energy penalty.

scholarly journals A Universal Porous Adsorbent for the Selective Capture of Carbon Dioxide

2019 ◽  
Author(s):  
Omid Taheri Qazvini ◽  
Shane G. Telfer
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Porous Materials ◽  
Noncovalent Interactions ◽  
Metal Organic Framework ◽  
Time Lags ◽  
Guest Molecules ◽  
Energy Penalty ◽  
Carbon Dioxide Co2 ◽  
Short Time

<div>Efficient and sustainable methods for carbon dioxide (CO2) capture are essential. Its atmospheric</div><div>concentration must be reduced to meet climate change targets, and its remediation from chemical</div><div>feedstocks and natural gas is vital. While mature technologies involving chemical reactions that trap the</div><div>CO2 do exist, they have many drawbacks. Porous materials with void spaces that are complementary in</div><div>size and electrostatic potential to CO2 offer an alternative. In these materials, the molecular CO2 guests</div><div>are trapped by noncovalent interactions, hence they can be recycled by releasing the CO2 with a low</div><div>energy penalty. Porous materials that are selective towards CO2 when it is present with an array of</div><div>competing gases are challenging to produce. Here, we show how a metal-organic framework, termed</div><div>MUF-16 (MUF = Massey University Framework), is a ‘universal’ adsorbent for CO2 that sequesters</div><div>CO2 from a broad palette of gas streams with record selectivities over competing gases. The position of</div><div>the CO2 molecules captured in the framework pores was determined crystallographically to illustrate</div><div>how complementary noncovalent interactions envelop the guest molecules. The pore environment has a</div><div>low affinity for all other gases, which underpins the benchmark selectivity of MUF-16 for CO2 over</div><div>methane, hydrogen and acetylene. Breakthrough gas separations under dynamic conditions benefit from</div><div>short time lags in the elution of the weakly-adsorbed component to deliver a repertoire of high-purity</div><div>products. MUF-16 is an inexpensive, robust, easily regernarable and recyclable adsorbent that is</div><div>universally applicable to the removal of CO2 from sources such as natural gas, syngas and chemical</div><div>feedstocks.</div>

scholarly journals A kinetic evaluation on no2 formation in the post-flame region of pressurized oxy-combustion process

2020 ◽  
pp. 236-236
Author(s):  
Xuebin Wang ◽  
Gaofeng Dai ◽  
Gregory Yablonsk ◽  
Milan Vujanovic ◽  
Richard Axelbaum
Keyword(s):  
Power Plants ◽  
Combustion Process ◽  
Strong Acid ◽  
Dew Point ◽  
Kinetic Evaluation ◽  
Atmospheric Air ◽  
Energy Penalty ◽  
Flame Region ◽  
No2 Formation ◽  
Time Required

Pressurized oxy-combustion is a promising technology that can significantly reduce the energy penalty associated with first generation oxy-combustion for CO2 capture in coal-fired power plants. However, higher pressure enhances the production of strong acid gases, including NO2 and SO3, aggravating the corrosion threat during flue gas recirculation. In the flame region, high temperature NOx exists mainly as NO, while conversion from NO to NO2 happened in post-flame region. In this study, the conversion of NO ? NO2 has been kinetically evaluated under representative post-flame conditions of pressurized oxy-combustion after validating the mechanism (80 species and 464 reactions), which includes nitrogen and sulfur chemistry based on GRI-Mech 3.0. The effects of residence time, temperature, pressure, major species (O2/H2O), and minor or trace species (CO/SOx) on NO2 formation are studied. The calculation results show that when pressure is increased from 1 to 15 bar, NO2 is increased from 1 to 60 ppm, and the acid dew point increases by over 80?C. Higher pressure and temperature greatly reduce the time required to reach equilibrium, e.g., at 15 bar and 1300?C, equilibrium is reached in 1 millisecond and the NO2/NO is about 0.8%. The formation and destruction of NO2 is generally through the reversible reactions: NO+O+M=NO2+M, HO2+NO=NO2+OH, and NO+O2=NO2+O. With increasing pressure and decreasing temperature, O plays a much more important role than HO2 in the oxidation of NO. A higher water vapor content accelerates NO2 formation in all cases by providing more O and HO2 radicals. The addition of CO or SO2 also promotes the formation of NO2. Finally, NO2 formation in a Pressurized oxy-combustion furnace is compared with that in a practical atmospheric air-combustion furnace and the comparison show that NO2 formation in a Pressurized oxy-combustion furnace can be over 10 times that of an atmospheric air-combustion furnace.

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